The recent discovery of topological phases of condensed matter has recently spawned a quest for their classical analogs in other branches of physics. In wave physics, in particular, several proposals have been put forward to obtain artificial periodic materials with a topologically nontrivial band structure, leading to metamaterial analogs of topological insulators. In particular, these materials support backscattering-immune chiral wave transport on their edges, along with a remarkable topological resilience against a large class of defects and disorder. In this presentation, we review our recent theoretical and experimental work on acoustic and electromagnetic topological insulators. We discuss our strategies to break time-reversal symmetry to induce a non-zero Chern invariant in nonreciprocal acoustic metamaterials, and pseudospin engineering methods to induce topologically nontrivial subwavelength acoustic and electromagnetic states without breaking time-reversal symmetry. Our results may lead to a novel class of system that exploit topological protection to guide and manipulate waves in unprecedented ways.
Romain Christophe Rémy Fleury, Haoye Qin, Aleksi Antoine Bossart, Zhechen Zhang
Romain Christophe Rémy Fleury, Haoye Qin, Zhechen Zhang, Qiaolu Chen
Dirk Grundler, Mohammad Hamdi, Mingran Xu, Huixin Guo, Axel Johan Marie Deenen